Online sales are expected to cost the state and local governments more than $70 million in lost sales tax revenue. That's because online retailers who don't have operations in Ohio aren't required to collect sales tax. However, Ohio has a use tax which has been in place since the 1930s. It was put in place to deal with Ohioans going to other states to make tax-free purchases.

"To an extent it is an honor system," said Ohio Tax Commissioner Joe Testa.

There's really no efficient way to enforce the tax, but Testa says that doesn't mean you should just skip it. Some people choose to pay the tax immediately, while others make a lump-sum payment with their income taxes.

The state's Department of Taxation website,, has an online calculator that allows you to put in your zip code and find out how much your use tax would be.

Until Congress acts on a pending bill to mandate online retailers charge sales tax, the use tax is the only way for Ohio to recoup some of the lost revenue.

Websites for major retailers that have a store in Ohio, like Wal-Mart, Target, K-Mart, or Best Buy, do have to charge sales tax for online purchases.